A reactor is one of components in a circuit that boosts or lowers voltage. For example, Patent Literature 1 discloses a reactor that is used as a circuit component of a converter that is installed in a vehicle such as a hybrid vehicle. This reactor includes an annular-shaped magnetic core, a coil, a case and resin. The coil is disposed around an outer periphery of the magnetic core, the case houses an assembly of the magnetic core and the coil, and the resin, with which the case is filled, seals the assembly. A typical magnetic core includes a plurality of core pieces formed of a magnetic material and gap members formed of a non-magnetic material. In this structure, the core pieces and the gap members are bonded to each other using adhesive (0026 in Patent Literature 1). The magnetic core includes coil wound portions around which the coil is disposed and end cores around which the coil is not disposed. By disposing sleeve-like bobbins formed of an insulating material around the coil wound portions (0022 in Patent Literature 1), an insulation property between the magnetic core and the coil is improved. Furthermore, a pair of frame-like bobbins are arranged to clamp the coil from both ends of the coil so as to compress the coil. In order to maintain this compressed state, an assembly of the coil and the coil wound portions of the magnetic core is housed in a box-like inner case (FIG. 4 of Patent Literature 1).
In the above-described reactor, the sleeve-like bobbins and the coil having been separately fabricated are sequentially disposed around the outer peripheries of the coil wound portions. In this state, the coil wound portions are clamped using the frame-like bobbins and the end cores, and the coil wound portions and the end cores are bonded to each other using adhesive. The coil wound portions and the end cores are bonded to each other while clamping and compressing the coil using the frame-like bobbins.